I'm truly happy for you, that you're one of the many people in the world whose sleep schedules are not more tightly coupled to the patterns of the Sun. Many of us are not like you, and we suffer for the lack of empathy expressed by such anecdotes. I wish it were that easy for me.
Based on my reading, delayed sleep-phase disorder has two components: a natural sleep phase that is delayed from the societal norm, and an inability to adjust that sleep phase relative to solar activity. The sleep phase is not based on solar patterns directly, but is regulated by a couple of mechanisms, one of which is the circadian rhythm. The body regulates the circadian rhythm by the daily cycle of light -- but what I think most people don't realize is that this only makes the sleep cycle regular, periodic. It's the distinction between precision and accuracy: we are consistently off the bullseye.
Changing timezones only shifts where the bullseye is. We cope with that just as anybody does: the body regularizes to the new norm. We're still a fixed offset off of the bullseye.
There's a related disorder known as shift-work sleep disorder, where an individual normally exhibits a sleep phase compatible with societal norms, but when called on to adjust that sleep phase (e.g. for late-shift work) is consistently unable to do so. In other words, shift-work sleep disorder manifests only one of the two components of delayed sleep-phase disorder.
Your anecdote shows that you definitely don't have shift-work sleep disorder.
I don’t think I have any disorder of any sort, you are right.
But here’s the thing: I used to struggle horribly with all this societal nonsense about when to and not to sleep. For 30 years I was always waking up too late and feeling more comfortable staying up late. It sucked but I couldn’t for the life of me adjust.
Until one day I realized it’s just like timezones. I can use the same tricks I use to switch timezones. Like going to bed at a set time instead of waiting for my body to tell me it’s time for bed. Waking up at a set time etc
And ... it worked.
So all I’m saying is try it. If you have and it didn’t work, fine. But you’ll never know if you don’t try. For 30 years I was too stubborn to try and would fight to the death anyone who suggested I may not have a sleep phase shift thingy and just aren’t going to bed early enough.
Also if you say you are so very tied to signals for the sun. What happens in the summer when it’s light out from 6am to 9pm? Do you also start waking up earlier? What about in winter when it’s light only from 9am to 4pm? How do you cope?
What do you do if you live in Finland and it’s light out for 6 months? Do you just not sleep?
> So all I’m saying is try it. If you have and it didn’t work, fine. But you’ll never know if you don’t try.
This is good advice, especially when -- as others in this thread have mentioned -- blue light exposure may be making artificial night owls out of larks. I personally have tried this without success. I use f.lux to avoid making my situation any worse.
> Also if you say you are so very tied to signals for the sun.
That's not quite what I said, but I understand why that was your takeaway.
> What happens in the summer when it’s light out from 6am to 9pm? Do you also start waking up earlier? What about in winter when it’s light only from 9am to 4pm? How do you cope?
This is a good question. I would categorize this under "second-order effects", because I'm certainly delayed year-round, and I haven't noticed any obvious seasonal variation. It would be interesting to see whether earlier dusk correlates with going to sleep earlier more easily. Thanks for the idea!
> What do you do if you live in Finland and it’s light out for 6 months? Do you just not sleep?
Like I said, the circadian rhythm is just one mechanism the body uses to regular sleep. Another is the build-up of adenosine accrued while awake. Mentioned elsewhere in this thread, the book "Why We Sleep" by Matthew Walker is a wonderful exploration of the complexity of our sleep subsystem.
As for myself, although I've never lived in Finland, I have been a grad student living like a hermit in a room with almost solely artificial lighting. My sleep cycle starts to wander: every "night", I go to bed later and later, and wake later and later. It sometimes got to the point that I would wake at 4pm and sleep at 7am -- and eventually I would cycle back around to a lark's early morning schedule. This is pretty consistent with experiments in which people live underground and never see light, although it's certainly not so extreme as the results they saw.
(This, by the by, is also how I know what my natural sleep period is when unconstrained by scheduled obligations: nine hours. I've noticed that seven hours is the absolute minimum I need to be remotely productive the next day, and even then I'm likely to do low-effort things like discuss sleep on Hacker News.)
> This, by the by, is also how I know what my natural sleep period is when unconstrained by scheduled obligations: nine hours.
I think this is my one super power. When unconstrained by social obligations and only working on things I'm excited about, my natural sleep period falls down as low as 4 hours. Normally I sleep 6 hours and on the weekends it goes up to 8 because I'm tired from the week.
But put me in vacation mode and after 2 days of rest I basically don't sleep anymore. It's weird.
Maybe that's what helps me adjust. I'm essentially cheating by sleeping less.
For me what causes schedule drift like you mentioned in the hermit situation is a combination of procrastination and excitement about interesting work. When it's time to go to bed, I say "Just 5 more minutes" and keep going. Suddenly it's 3am and then of course I'm not going to get up at 7am.
The next day it's evening and well I got up late today so obviously I'm not tired yet ... aaand it's a self-reinforcing cycle.
I have seen good results from forcefully cutting that cycle and enforcing a bed time. It takes discipline to stop what I'm doing and go to bed, but ultimately it's the only thing that seems to work. Usually once I'm in bed there's no problem falling asleep within 10 minutes or so. The hard part is convincing myself to get to bed.
Based on my reading, delayed sleep-phase disorder has two components: a natural sleep phase that is delayed from the societal norm, and an inability to adjust that sleep phase relative to solar activity. The sleep phase is not based on solar patterns directly, but is regulated by a couple of mechanisms, one of which is the circadian rhythm. The body regulates the circadian rhythm by the daily cycle of light -- but what I think most people don't realize is that this only makes the sleep cycle regular, periodic. It's the distinction between precision and accuracy: we are consistently off the bullseye.
Changing timezones only shifts where the bullseye is. We cope with that just as anybody does: the body regularizes to the new norm. We're still a fixed offset off of the bullseye.
There's a related disorder known as shift-work sleep disorder, where an individual normally exhibits a sleep phase compatible with societal norms, but when called on to adjust that sleep phase (e.g. for late-shift work) is consistently unable to do so. In other words, shift-work sleep disorder manifests only one of the two components of delayed sleep-phase disorder.
Your anecdote shows that you definitely don't have shift-work sleep disorder.